


When the Darkness Comes

by YuiMukami



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Vampire, Angst, Angst with a Happy Ending, F/M, Female My Unit | Byleth, Hurt/Comfort
Language: English
Status: In-Progress
Published: 2020-01-08
Updated: 2020-01-15
Packaged: 2021-02-27 12:08:58
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,334
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22176832
Author URL: https://archiveofourown.org/users/YuiMukami/pseuds/YuiMukami
Summary: "Can we talk? Please?""There's nothing to discuss," Dimitri growled. Byleth hesitantly reached out for his arm, but he suddenly whirled around, startling her. He smirked. "You claim not to fear me, but I know you do. You're no different from anyone else, Professor.""That's not-"Dimitri bared his fangs with a snarl and Byleth unconsciously took a step back. He glared at her, silently challenging her to disagree with him again.
Relationships: Dimitri Alexandre Blaiddyd & My Unit | Byleth, Dimitri Alexandre Blaiddyd/My Unit | Byleth
Comments: 9
Kudos: 62





	1. Monsters Among Men

_Professor, huh_ , Byleth thought as she made her way around the monastery. She had no idea what Rhea was thinking, making her a professor after minutes of knowing her. Seemed like she hadn’t even shared her idea with her own staff, given how Seteth had reacted as well. She let out a sigh. _I’ve never taught a day in my life,_ she thought. _These kids are in for a disappointment_.

Those "kids," as it turned out, were nearly all around her own age. Hardly children at all. Some of them, she later learned, were even a year or two older. Clearly, she had to be doing something right, because after her first month or so of teaching, she already had students from other houses wanting to transfer to her class.

When given the choice, Byleth had chosen the Blue Lion House. It was a hard decision, as she had taken a liking to Claude of the Golden Deer almost immediately. Edelgard of the Black Eagles had been particularly interested in her and the feeling had been mutual. But in the end, it was the Blue Lions that had won her over. Specifically, their House Leader, Dimitri. Byleth supposed some long forgotten girlish part of her was thrilled at meeting a real prince based on the way her stomach fluttered whenever he greeted her. So casual. But then again, she’d never been used to formalities.

When word got around that Jeralt was the new professor’s father, Leonie of the Golden Deer had immediately transferred to her class. After Byleth’s teaching skills clearly proved to be impressive, she’d had Linhardt of the Black Eagles and Lysithea, Marianne, and Hilda also of the Golden Deer transfer into her class as well.

The former mercenary fell into a steady rhythm eventually. Mornings were spent teaching. Afternoons were spent eating with her students and fellow staff members. Afternoons were for training. Evenings were spent however she wished. Lately, she’d been spending a lot of time training with Dimitri and Felix. Although, some nights, she would venture over to the library and find Linhardt lost in some book that Seteth would inevitably snatch away. But that never seemed to deter the young mage.

After one morning of a particularly exhausting lesson, it was finally time for lunch, and Byleth dragged herself into the dining hall. She was so tired from teaching all morning that she barely paid attention to the food she ordered. She carried her plate across the room, scanning the crowd for any familiar faces. She spotted an empty seat across from Linhardt, who had his nose stuck in a book, and hurried over to join him.

“Hello, Professor,” Linhardt lazily greeted her without looking up from his book.

“What are you reading?” she asked, trying to catch a glimpse of the cover. Linhardt held the book up momentarily to show her the title. “Magical Creatures of Fodlan? Really?”

“He’s such a nut about that kind of thing,” said Lysithea, setting her plate down next to Linhardt’s barely touched one. “Crests, vampires, werewolves, he never shuts up.”

“It really is quite fascinating,” Linhardt replied. Byleth nodded slowly, not quite convinced. The mage ignored the two girls, who had begun to chat, and was soon lost in his book once again.

“Would it be alright if I joined you?” All three of them looked up to see Dimitri hovering close by. Byleth gave him a small smile as she patted the empty seat next to her and the prince’s face momentarily lit up. “Thank you, Professor. Sorry to disturb you.” He nodded at Linhardt and Lysithea in greeting. Linhardt gave a distracted wave in return.

Dimitri attempted to make awkward small talk while he and Byleth ate. Suddenly, Linhardt slammed his book down.

“Professor, you used to be a traveling mercenary with Jeralt, right?” Byleth nodded, unsure of where he was going with this. “That means you’ve been just about everywhere and seen things most people never will in their lifetimes.”

“I wouldn’t say everywh-”

“Tell me,” Linhardt continued, ignoring her comment. “Did you ever come across any vampires during your travels?”

Byleth sensed Dimitri stiffen beside her. She paused to think. “Yes, I’ve seen a couple, but I don’t enjoy fighting them. They’re strong.”

“They’re despicable.” Dimitri muttered darkly. Byleth, Linhardt, and Lysithea turned to stare at him, eyes wide. “They live alongside us, pretending to be civilized, when they are really just wolves in sheep’s clothing.” The prince’s eyes were hard and his hands had clenched into fists. “Monsters among men.”

“Dimitri...” Byleth gently called out to him and placed a hand over one of his clenched fists. He seemed to snap out of his sudden dark mood and his eyes widened slightly.

“Ah, my apologies,” he said quickly. “I had a bad experience with vampires four years ago.” He attempted to wave it off as nothing, but Byleth could see something sad and lonely behind his eyes. She wanted to reach out to him, but it was almost as if, for a moment, the prince had gone somewhere she couldn’t reach him.


	2. Thicker Than Blood

**Notes for the Chapter:**

> I'm so sorry this is probably really messy. I'm just trying to get to the timeskip as quickly as possible. I'm trying to keep a weekly schedule of posting new chapters on Wednesdays, so hopefully I'll be able to keep it up. As always, thank you for reading and I hope you enjoy!

_“Did you hear?”_

_“Hear what?”_

_“About the Death Knight?”_

_“The what?!”_

_“He wanders around at night, killing anyone who crosses his path.”_

_“No way. You’re lying!”_

_“Nuh-uh, I overheard one of the knights talk about it this morning.”_

_“How could anyone do that to another person?”_

_“That’s the thing – there’s a rumor that he’s not even human. He’s a – ”_

Dimitri slammed his book shut and the whispers ceased immediately. He heard the scuffle of chairs as the other students ran out of the library. He closed his eyes and sighed, running a hand through his hair.

Vampires. Always, always vampires.

“What the hell’s the matter with you?”

Dimitri opened his eyes and slowly turned his head to see Felix standing in the doorway, his arms crossed over this chest. His friend’s tone indicated he had watched the whole scene unfold.

“What is it Felix?”

“It’s time for class, boar. Hurry up.” Without waiting, Felix turned on his heel and stalked off. Dimitri let out another sigh and stood up to push his chair in. He gathered his books and tried to calm his growing anxiety.

~~

Class seemed agonizingly long today. While he normally sat in the front row and was enthusiastic about learning from Byleth, today he found he could not concentrate. A headache had started to come on after the incident in the library and only worsened throughout the day. After lectures, Byleth’s face turned grim.

“Our mission for this month,” she began, “is to search for Flayn.”

“Seteth’s younger sister?” Annette asked. Byleth nodded.

“Yes. Apparently, she’s gone missing. I want everyone to split up into groups and spend the remainder of the afternoon searching for her. I will help as well.”

With that, the Blue Lions broke into smaller groups and scattered across the monastery grounds, searching for any clues as to Flayn’s whereabouts. When Byleth came to him hours later, Dimitri’s mood darkened even more as she voiced her suspicions.

“So, you believe Professor Jeritza is responsible for Flayn’s kidnapping,” he said. Byleth nodded. “And Professor Manuela is missing as well?” Another nod. They gathered the rest of the class and proceeded to investigate Jeritza’s quarters. Upon arrival, an unconscious Manuela was found and Dimitri was roped into carrying her to the infirmary with Professor Hanneman. He felt bad for having to leave his classmates, but he wasn’t exactly given a choice in the matter.

“What happened to her?” a nurse asked as Dimitri and Hanneman entered the infirmary. She took Manuela from the two and Dimitri gave a hurried explanation.

“Check to see if she was bitten,” Professor Hanneman added. “There’s a rumor about this Death Knight character terrorizing the nearby villages along with some vampires who appear to be under his command.”

“Yes, of course,” the nurse responded. “I have treated some of the townspeople. Sadly, we lost a few. Their bodies were burned to ensure they would not revive as vampires themselves.”

“Actually,” Hanneman interrupted, “the only way to kill a vampire is to cut off its head.”

Dimitri stopped listening.

_Death Knight_.

Images began to flash before the prince’s eyes.

_Vampires under his command_.

Flames everywhere. Dead bodies littering the area surrounding him.

_Their bodies were burned_.

Glenn. His friends. Some were mauled beyond recognition.

_Cut off its head_.

His father, his head severed from his body.

_Your fault. You survived. You should have died. Your fault_.

“Dimitri?” Hanneman’s voice cut through the images and the whispers of the dead. It took the prince a moment to come back to reality. Both the nurse and the professor were staring at him in concern.

“Wh-what is it?” Dimitri silently cursed himself for the way his voice shook. He wiped sweat from his forehead.

“Manuela is going to be fine,” Hanneman said slowly, still watching the prince. “You should return to your classmates.”

“Y-yes, of course,” the prince replied. “My apologies.” He gave a slight bow before departing the infirmary as quickly as he could.

By the time he’d caught up with his classmates, Flayn had been found and returned safely. He walked in on Seteth thanking Byleth. He stood a respectful distance away, silently observing her. As Seteth continued speaking, a small smile appeared on her lips. Dimitri’s heart skipped a beat. No, must have imagined it.

“Dimitri!” Byleth called out after bidding Seteth farewell. She trotted over to him and Dimitri could have sworn she must have heard the pounding of his heart. Sure enough, there was that smile. She was smiling at him.

“Professor,” he breathed. He shook his head, scolding himself for allowing himself to be distracted. “I apologize for returning as soon as everything ends.”

“Don’t worry about it,” Byleth replied. “How is Manuela?”

“Professor Manuela will be fine,” Dimitri said slowly, trying not to recall the incident in the infirmary. Byleth’s eyebrows furrowed.

“How are you? You look a bit unwell.”

“I...” Her question caught him off-guard. “I am fine. I’ve had a bit of a headache since this morning, but it’s nothing to worry yourself over.”

She cocked her head to the side. “Still, if you’re not feeling well...”

Dimitri’s attention focused on something over her shoulder. Someone, no, two people were approaching. At first, he had assumed it to be other students, but upon closer inspection, he found he didn’t recognize either one. The prince’s eyes widened as he suddenly recalled Professor Hanneman’s words.

_“There’s a rumor about this Death Knight character terrorizing the nearby villages along with some vampires who appear to be under his command.”_

“Professor, watch out!” Dimitri shouted, jumping in front of her, lance in hand.

The creatures hissed. One wielded magic while the other drew a sword.

“Vampires.” Byleth was suddenly beside him. She drew her sword and fell into a battle stance. “I should have known after fighting the Death Knight.” With a cry, she started forward. Dimitri’s grip on his lance tightened. The vampires had begun to charge as well.

“Professor!” He was beside her, fighting off the vampire with the sword while she focused on the magic wielder. Although Byleth and Dimitri were strong, the vampires were stronger. Students began gathering, then shrieking in fear when they saw the vampires.

“Someone go and get Lady Rhea!” Dimitri turned his head at the sound of Mercedes’ voice, checking to see if she was safe. The minor distraction cost him.

“Dimitri, watch out!” Byleth was suddenly in front of him. She cried out in pain and dropped her sword. She was bleeding. Dimitri’s eyes widened in horror as he realized she had taken a blow meant for him.

Now that a crowd had gathered, the two vampires backed off, and then vanished in an instant. Everything seemed to be moving in slow motion. Rhea had arrived. She shoved people out of her way as she came to Byleth’s aid. Mercedes and Marianne were also by her side, trying to heal the wound on her shoulder. Ashamed, Dimitri dropped his lance and ran.

~~

Byleth recovered quickly, but Dimitri had been avoiding her for days. If they made eye contact, he would hurriedly look away. He had an excuse every time Felix wanted him to train with the professor. He stopped coming to the dining hall.

One night, after leaving the library, he ran into her on his way back to his room and knew he could no longer avoid her.

“You’re up late,” she observed. “Studying?”

“Something like that,” he replied, looking at anything but her.

“Dimitri...” Now she was the one averting her gaze. “I know you’ve been avoiding me. Have I done something to upset you?”

“What? No! Of course not!” Byleth looked up and met his gaze. He let out a long sigh and hesitated before speaking. “How familiar are you with the Tragedy of Duscur?”

“I’ve heard of it,” she replied, tilting her head slightly to one side. “Why?”

“Four years ago, my entire family was murdered,” he said quietly. “Vampires were largely responsible.” And so, he began to tell her the story of his past. He told her everything, from losing his father to his decision to come to the Officer’s Academy. Byleth listened, occasionally nodding to show she was listening. When he finished, Dimitri was on the brink of tears. Byleth was quiet, her expression thoughtful. The prince looked away. He wasn’t sure he could take it if she were to judge him or respond negatively.

“Dimitri,” her voice was soft. Dimitri felt something warm touch his hand. He looked down to see her holding his hand in her own. “I’m so sorry. I didn’t know.”

“You have nothing to apologize for,” he said, still staring at their intertwined hands.

“You’re not alone anymore,” she told him. “You’ll be okay.”

“Professor...” Dimitri found he could barely speak. He squeezed her hand gently, hoping she would understand his feelings through the gesture.

He smiled when she squeezed his hand back.

**Author's Note:**

> This is something I've wanted to do for a long time and I'm just now getting around to it haha
> 
> I was inspired by some Vampire Edelgard fics I've seen around here. I don't think I'd be able to do my wife justice, so here's Vampire Dimitri instead.
> 
> Sorry the first chapter is so short. I think most of the initial chapters will be since Dimitri won't become a vampire until after the timeskip. The rating might change due to later chapters. Anyways, I really hope you enjoy reading this!


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